Method and apparatus for detecting sync mark

ABSTRACT

Aspects of the disclosure provide a method for detecting marks. The method includes receiving a data signal from a channel. Further, the method includes matching the data signal to a template that corresponds to a predetermined pattern transmitted over the channel to detect marks, prior to decoding the data signal into a decoded bit stream.

INCORPORATION BY REFERENCE

This application claims the benefit of U.S. Provisional Application No.61/355,489, “Detect Syncmark by Matched Filter” filed on Jun. 16, 2010,which is incorporated herein by reference in its entirety.

BACKGROUND

The background description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent the work is described in thisbackground section, as well as aspects of the description that may nototherwise qualify as prior art at the time of filing, are neitherexpressly nor impliedly admitted as prior art against the presentdisclosure.

Generally, massive storage, such as optical storage, magnetic storage,and the like, stores user data in a bit stream that uses synchronization(sync) marks having a predetermined unique pattern to frame user data.In an example, Blu-ray standard includes a 9T9T pattern in sync marks.The 9T9T pattern has nine zeroes followed by nine ones or nine onesfollowed by nine zeros. When a reading device detects a 9T9T pattern ina bit stream read from a Blu-ray disc, the reading device knows astarting position of a frame of user data in the bit stream. However,when sync mark detection is based on extracted bit stream, errors in thebit detection can increase sync mark detection errors.

SUMMARY

Aspects of the disclosure provide a method for detecting marks, such assync marks. The method includes receiving a data signal from a channel.Further, the method includes matching the data signal to a template thatcorresponds to a predetermined pattern transmitted over the channel todetect marks, prior to decoding the data signal into a decoded bitstream.

To match the data signal to the template, the method includes matchingthe data signal to a sync mark template that corresponds to a sync markpattern transmitted over the channel to detect sync marks in the datasignal. The sync marks are used to frame user data in the data signal.

Further, in an embodiment, to match the data signal to the template, themethod includes matching the data signal to a non-uniformly weightedtemplate. In an example, the method includes convolving thepredetermined pattern with a partial response target that characterizesthe channel to calculate a first template, and weighting the firsttemplate non-uniformly to generate a second template.

According to an aspect of the disclosure, the method includescalculating correlation coefficients between the data signal and thetemplate, and detecting the marks based on the correlation coefficients.It is noted that when a calculated correlation coefficient has negativevalue, the method includes calculating an absolute value of thecorrelation coefficient. In an example, to detect the marks based on thecorrelation coefficients, the method includes detecting peak tops in thecorrelation coefficients that are larger than neighboring correlationcoefficients, and comparing the peak tops to a threshold to detect themarks. In another example, to calculate the correlation coefficientsbetween the data signal and the template, the method includes storing apre-calculated statistical value of the template, such as Euclideannorm, standard deviation, and the like, and calculating the correlationcoefficients using the stored statistical value of the template.

Aspects of the disclosure provide a signal processing circuit. Thesignal processing circuit includes a pre-decoding portion, a decoder anda mark detection module. The pre-decoding portion is configured toreceive a signal corresponding to a bit stream that includes markshaving a predetermined pattern, process the signal, and output a datasignal for decoding. The decoder is configured to decode the data signalinto a decoded bit stream. The mark detection module is configured tomatch the data signal to a template that corresponds to thepredetermined pattern to detect the marks.

Aspects of the disclosure also provide an electronic system. Theelectronic system includes a pick-up unit, a pre-decoding portion, adecoder, and a mark detection module. The pick-up unit is configured togenerate a signal corresponding to a bit stream. The bit stream includesmarks having a predetermined pattern. The pre-decoding portion isconfigured to process the signal, and output a data signal for decoding.The decoder is configured to decode the data signal into a decoded bitstream. The mark detection module is configured to match the data signalto a template that corresponds to the predetermined pattern transmittedover a channel to detect the marks. In an example, the channel includesthe pick-up unit and the pre-decoding portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of this disclosure that are proposed as exampleswill be described in detail with reference to the following figures,wherein like numerals reference like elements, and wherein:

FIG. 1 shows a block diagram of an electronic system example 100according to an embodiment of the disclosure;

FIG. 2 shows a block diagram of a data read channel example 230according to an embodiment of the disclosure;

FIG. 3 shows a block diagram of a synchronization (sync) mark detectionmodule 380 according to an embodiment of the disclosure;

FIG. 4 shows a flow chart outlining a process example 400 for a syncmark detection module to detect sync marks according to an embodiment ofthe disclosure;

FIG. 5A shows examples of generating sync mark templates according to anembodiment of the disclosure;

FIG. 5B shows a plot of sync mark templates according to an embodimentof the disclosure;

FIGS. 6A-6C show plots of sync mark detection according to an embodimentof the disclosure;

FIG. 7A shows a performance example of an electronic system according toan embodiment of the disclosure; and

FIG. 7B shows a performance example of a comparison electronic system.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows a block diagram of an electronic system example 100according to an embodiment of the disclosure. The electronic system 100includes a receiving and extracting portion 110 that receives a signal102 corresponding to a bit stream that includes marks of a predeterminedpattern. In an example, the bit stream includes synchronization (sync)marks having a predetermined pattern to frame user data. The receivingand extracting portion 110 processes the signal 102 and extracts the bitstream from the signal 102. According to an aspect of the disclosure,the receiving and extracting portion 110 detects sync marks based on anintermediate signal during processing, instead of the extracted bitstream.

In an embodiment, the receiving and extracting portion 110 includes apick-up unit 120 and a signal processing circuit 130. The pick-up unit120 receives the signal 102 and suitably generates an electrical signal135 in response to the signal 102. The signal processing circuit 130processes the electrical signal 135, and extracts the bit stream.

It is noted that the signal 102 can be any suitable signal. In anembodiment, the signal 102 is generated in response to a bit streamstored on a storage medium 101. It is noted that the storage medium 101can be any suitable storage medium. In an example, the storage medium101 is a hard disk drive that stores the bit stream as magnetic fieldchanges. The pick-up unit 120 includes a magnetic head that generatesthe electrical signal 135 in response to the magnetic field changes onthe storage medium 101. The signal processing circuit 130 processes theelectrical signal 135 and extracts the bit stream.

In another example, the storage medium 101 is an optical disc, such ascompact disc (CD), digital versatile disc (DVD), Blu-ray disc, and thelike, that stores the bit stream as optical property changes. Thepick-up unit 120 is an optical pick-up unit that generates theelectrical signal 135 in response to the optical property changes.Specifically, the pick-up unit 120 directs a light beam to the storagemedium 101. The light beam is reflected from the storage medium 101. Thesignal 102, which is the reflected light beam, has light properties thatcorrespond to the optical property changes on the storage medium 101.The pick-up unit 120 generates the electrical signal 135 in response tothe light properties of the signal 102. The signal processing circuit130 processes the electrical signal 135 and extracts the bit stream.

In another embodiment, the signal 102 is an electromagnetic signaltransmitted in the air, for example, from a base station (not shown).The pick-up unit 120 includes an antenna that suitably generates theelectrical signal 135 in response to the electromagnetic signal 102. Thesignal processing circuit 130 processes the electrical signal 135 andextracts the bit stream.

In the FIG. 1 example, the signal processing circuit 130 includes apre-decoding portion 131, a decoder 170 and a sync mark detection module180. The pre-decoding portion 131 processes the electrical signal 135 toprepare the electrical signal 135 for decoding. The pre-decoding portion131 outputs a data signal 165. The decoder 170 makes bit decisions basedon the data signal 165 to extract the bit stream. The sync markdetection module 180 detects sync marks based on the data signal 165.

According to an aspect of the disclosure, the decoder 170 may make wrongbit decisions and throw out useful information for sync mark detection.When sync mark detection is based on the data signal 165 prior to thebit decisions, the sync mark detection can use suitable information inthe data signal 165 to reduce detection errors.

It is noted that the electronic system 100 can include other suitablecomponents (not shown), such as processor, user input module,audio/video module, and the like.

FIG. 2 shows a block diagram of a signal processing circuit example 230according to an embodiment of the disclosure. The signal processingcircuit 230 includes a pre-decoding portion 231, a decoder 270, and async mark detection module 280. The pre-decoding portion 231 receives anelectrical signal 235, processes the electrical signal 235, and providesa processed electrical signal, such as a data signal 265, to the decoder270 and the sync mark detection module 280. The decoder 270 makes bitdecisions based on the data signal 265 to extract a bit stream. The syncmark detection module 280 detects sync marks based on the data signal265. These elements are coupled together as shown in FIG. 2.

The pre-decoding portion 231 includes any suitable elements to processthe electrical signal 235. In an embodiment, the pre-decoding portion231 includes a front-end analog portion 240, an analog to digitalconverter (ADC) 250, a timing module 252, and an equalizer 260. Theseelements are coupled together as shown in FIG. 2.

The front-end analog portion 240 receives the electrical signal 235,regulates the electrical signal, and outputs an analog data signal 245.The front-end analog portion 240 regulates the electrical signal 235using analog techniques, such as amplification, compensation foroffsets, adjusting an appropriate dynamic range, and the like. Thus, theanalog data signal 245 is suitable for subsequent circuit components tohandle.

The ADC 250 receives the analog data signal 245 and samples the analogdata signal 245 based on a sampling clock 256 provided by the timingmodule 252. Further, the ADC 250 converts the sampled signal into adigital signal 255. In an embodiment, the timing module 252 and the ADC250 forms a timing loop. The timing module 252 generates the samplingclock 256 based on the digital signal 255. It is noted that, in anotherembodiment, the timing loop includes other elements, such as theequalizer 260.

The equalizer 260 receives the digital signal 255, shapes the digitalsignal 255, and outputs a shaped digital signal, such as the data signal265. In an embodiment, the equalizer 260 is a finite impulse response(FIR) digital filter that is configured to shape the digital signal 255according to a partial response target to reduce noises from the digitalsignal 255 and control inter-symbol interferences. In an example, thepartial response target characterizes a channel for conveying the bitstream. For example, the partial response target collectivelycharacterizes a channel that includes the pick-up unit 120 forgenerating the electrical signal 135 in response to the bit stream readfrom the storage medium 101 and the pre-decoding portion 165 forprocessing the electrical signal 135. It is noted that the partialresponse target can be fixed, programmable or adaptive.

The decoder 270 extracts the bit stream from the data signal 265. Thedecoder 270 can use any suitable technique to extract the bit stream. Inan embodiment, the detector 270 includes a Viterbi detector 275 thatmakes bit decisions according to a Viterbi algorithm.

The sync mark detection module 280 detects sync marks based on the datasignal 265 instead of the extracted bit stream. In an embodiment, thesync mark detection module 280 uses a matched filter to match the datasignal 265 with a template that characterizes a sync mark pattern in achannel that conveys the bit stream to detect sync marks from the datasignal 265. Specifically, in an embodiment, the sync mark detectionmodule 280 includes a template module 282, a correlation module 284 anda detector 286. These elements are coupled together as shown in FIG. 2.

The template module 282 provides a template that characterizes the syncmark pattern in the channel. In an embodiment, the template ispredetermined and stored in a memory (not shown) associated with thetemplate module 282. During operation, the memory provides the storedtemplate.

It is noted that sync marks for different storage media may includedifferent patterns. The template module 282 may store templates inassociation with corresponding storage mediums. Based on a storagemedium, the template module 282 provides the corresponding template forthe storage medium.

In another embodiment, the template module 282 includes a partialresponse target 283 that characterizes the channel for conveying the bitstream. During operation, based on a storage medium, the template module282 calculates the template for the storage medium by convolving a syncmark for the storage medium with the partial response target 283. It isnoted that the partial response target 283 can be programmable oradaptively updated.

It is also noted that the template can be further adjusted to improvesync mark detection accuracy. In an embodiment, the template is weighedaccording to weight windows to emphasize or deemphasize differentportions of the template.

The correlation module 284 calculates correlation coefficients betweenthe data signal 265 and the template. In an example, the template is ina form of a N-tuple vector (N is a positive integer), and the datasignal 265 is in a form of a discrete-time signal. At each time point,the most recent N time points of the data signal 265 form a N-tuple datavector, and the correlation module 284 calculates a correlationcoefficient between the data vector and the template vector for the timepoint.

It is noted that the correlation module 284 can use any suitabletechniques to reduce calculation complexity. In an example, acorrelation coefficient is calculated using Eq. 1:

$\begin{matrix}{{C( {X,Y} )} = \frac{\sum{x_{i}y_{i}}}{\sqrt{( {\sum x_{i}^{2}} )( {\sum y_{i}^{2}} )}}} & {{Eq}.\mspace{14mu} 1}\end{matrix}$where X denotes the template vector, and Y denotes the data vector. Inan example, the correlation module 284 pre-calculates a Euclidean normof the template vector (Σx_(i) ²) and stores the Euclidean norm in amemory. Thus, the correlation module 284 uses the stored Euclidean normof the template vector to calculate the correlation coefficients betweenthe data signal 265 and the template.

The detector 286 compares the correlation coefficients with a threshold287 to detect sync marks. For example, when an absolute value of acorrelation coefficient is larger than the threshold 287, the sync markdetection module 280 detects a sync mark. It is noted that, in anembodiment, the threshold 287 is pre-calibrated to have a reduced numberof detection errors.

FIG. 3 shows a block diagram of a synchronization (sync) mark detectionmodule 380 according to an embodiment of the disclosure. The sync markdetection module 380 includes a window template module 382, acorrelation module 384, and a detector 386. These elements are coupledtogether as shown in FIG. 3.

The window template module 382 stores a partial response target 383 thatcharacterizes a channel for conveying the bit stream and a weight window381 that defines weights for emphasizing or de-emphasizing differentportions of a template. In an embodiment, the window template module 382convolves the partial response target 383 with a sync mark to calculatea template. Further, the window template module 382 weights the templateaccording to the weight window 381 to determine a windowed template.

The correlation module 384 receives a data signal 365, and calculatescorrelation coefficients between the data signal 365 and the windowedtemplate.

The detector 386 includes a peak top detector 388 and a threshold 387.The peak top detector 388 detects peak tops in the correlationcoefficients that are larger than neighbor correlation coefficients.Then, the detector 386 compares the peak tops with the threshold 387 todetect sync marks.

It is noted that the weighting operation can be performed using othersuitable techniques. In an example, the template is not weighted,however, the correlation module 384 is configured to weight differentportions differently. For example, the correlation module 384 isconfigured to heavily weight transition portions, and lightly weightflat portions.

FIG. 4 shows a flow chart outlining a process example 400 for a syncmark detection module, such as the sync mark detection modules 180, 280and 380, to detect sync marks according to an embodiment of thedisclosure. The process starts from S401 and proceeds to S410.

At S410, the sync mark detection module determines a template for syncmark detection. In an example, the sync mark detection module storespredetermined templates in association with storage media in a memory.Then, a storage medium is identified. Based on the identified storagemedium, the sync mark detection module reads the stored template inassociation with the storage medium. For example, an optical disc storesdisc and format information, such as disc category, version number, andthe like, in a control data zone on the optical disc. The disc andformat information can be read to identify the optical disc. Based onthe identified optical disc, the sync mark detection module reads thestored template in association with the optical disc.

In another example, the sync mark detection module stores a partialresponse target that characterizes a channel for conveying a bit streamthat includes the sync marks. Further, the sync mark detection moduleconvolves the partial response target with a sync mark for a storagemedium to determine a template for the storage medium. In anotherexample, the sync mark detection module weights the template accordingto weight windows to determine a weighed template.

At S420, the sync mark detection module receives a data signal prior todecoding. The data signal corresponds to a bit stream that uses syncmarks to frame user data. In an embodiment, the data signal is outputfrom a pre-decoding portion, such as the pre-decoding portions 131, 231and the like, that prepares the data signal for decoding. Then, the datasignal is input to a decoder, such as a Viterbi decoder, that makes bitdecisions to extract the bit stream. Thus, the data signal is anintermediate signal prior to decoding. Information in the data signalcan be suitable used to increase sync mark detection accuracy.

At S430, the sync mark detection module calculates correlationcoefficients between the data signal and the template. In an example,the template is in the form of a N-tuple vector. The data signal is inthe form of a discrete-time signal. At each time point, the data signalof the most recent N time points form a N-tuple data vector, and thesync mark detection module calculates a correlation coefficient betweenthe template vector and the data vector for the time point.

At S440, the sync mark detection module detects sync marks based on thecorrelation coefficients. In an embodiment, the sync mark detectionmodule detects peak tops in the correlation coefficients. The peak topsare those correlation coefficients that are larger than their neighborcorrelation coefficients. Then, the sync mark detection module comparespeak tops with a threshold to detect sync marks. For example, the syncmark detection module compares absolute values of the peak tops with thethreshold. When an absolute value of a peak top is larger than thethreshold, the sync mark detection module detects a sync mark. Then, theprocess proceeds to S499 and terminates.

FIG. 5A shows an example 500A of generating a windowed templateaccording to an embodiment of the disclosure. In the example, a syncmark 510A includes a 9T9T (nine zeros followed by nine ones or nine onesfollowed by nine zeros) pattern. The sync mark 510A forms a vector 530Aby changing zeros to negative ones. Further, the vector 530A isconvolved with a partial response target 520A to determine a template540A. The template 540A is weighted according to a weight window 550A tocalculate the weighted template 560A.

FIG. 5B shows a plot 500B of the templates in FIG. 5A. The plot 500Bincludes a first curve 540B corresponding to the template 540A, and asecond curve 56013 corresponding to the windowed template 560A. Thewindowed template weights transition portions 570B heavier than the flatportions 580B. Thus, the transition portions 570B are emphasized and theflat portions 580B are de-emphasized.

It is noted that the partial response target 520A is merely an example.Other suitable partial response target is contemplated. It is also notedthat the weight window 550A is merely an example. Other suitable weightwindow is contemplated.

FIGS. 6A-6C show plots for a sync mark detection example according to anembodiment of the disclosure. FIG. 6A shows a data signal 610 in theform of discrete-time signal. In an example, the data signal 610corresponds to a bit stream read from a Blu-ray disc, and is output froma pre-decoding portion, such as the pre-decoding portion 231. Accordingto a Blu-ray standard, the sync mark includes a 9T9T pattern. Inaddition, an 8T8T pattern is legal for user data according to theBlu-ray standard. In FIG. 6A, the data signal 610 includes a firstportion 611 corresponding to a 8T8T pattern, and a second portion 612corresponding to a 9T9T pattern.

FIG. 6B shows correlation coefficients between the data signal 610 andthe template 540A. The first portion 611 of the data signal 610 has afirst correlation coefficient 621 to the template 540A. The secondportion 612 of the data signal 610 has a second correlation coefficient622 to the template 540A. It is noted that a difference between thefirst correlation coefficient 621 and the second correlation coefficient622 is relatively small. It is also noted that neighbor coefficients 623of the second correlation coefficient 622 also has relatively largevalues. In an embodiment, a threshold is suitably determined todiscriminate the first correlation coefficient 621 or the neighborcoefficients 623 from being detected as sync marks.

FIG. 6C shows correlation coefficients between the data signal 610 andthe windowed template 560A according to an embodiment of the disclosure.The first portion 611 of the data signal 610 has a third correlationcoefficient 631 to the windowed template 560A. The second portion 612 ofthe data signal 610 has a fourth correlation coefficient 632 to thewindowed template 560A.

Due to the reason that the weight window 550A emphasizes the transitionportions of template and de-emphasizes the flat portions of thetemplate, the third correlation coefficient 631 is reduced from thefirst correlation coefficient 621, and a difference between the thirdcorrelation coefficient 631 and the fourth correlation coefficient 632is relatively larger. In an embodiment, a threshold is suitablydetermined to discriminate the third correlation coefficient 631 frombeing detected as sync marks.

FIG. 6C also shows peak tops in the correlation coefficients that arelarger than neighbor correlation coefficients. The peak tops can be usedto discriminate neighbor coefficients from being considered as syncmarks.

FIG. 7A shows a performance table 700A of a Blu-ray system exampleaccording to an embodiment of the disclosure. The Blu-ray system matchesan intermediate signal, such as the data signal 365, with a windowedtemplate of a sync mark having 9T9T pattern to detect sync marks.According to an embodiment of the disclosure, a threshold can besuitably selected to reduce detection errors. Generally, the detectionerrors include both false detection errors and miss sync errors. When aportion of the data signal 365 does not include a sync mark, and theBlu-ray system detects a sync mark, the Blu-ray system has a falsedetection error. When a portion of the data signal 365 has a sync mark,and the Blu-ray system doesn't detect the sync mark, the Blu-ray systemhas a miss sync error.

The numbers of the false detection errors and the miss sync errorsdepend on the threshold used for sync mark detection. For example,increasing the threshold reduces false detection errors but increasesmiss sync errors, and reducing the threshold reduces miss sync errorsbut increases false detection errors. The threshold can be suitablyselected to reduce the total number of the detection errors.

The performance table 700A shows total detection errors in associationwith thresholds using a same input signal to the Bin-ray system. Thethreshold 0.94 is selected to achieve 13 detection errors in total.

FIG. 7B shows a performance table 700B of a comparison Blu-ray system.The comparison Blu-ray system matches an extracted bit stream with async mark pattern, such as 9T9T, to detect sync marks. The performancetable 700B shows total detection errors in association with thresholds.It is noted that the same input signal is provided to the Blu-ray systemin FIG. 7A and the comparison Blu-ray system in FIG. 7B. According tothe performance table 700B, the threshold 21 is selected to achieve 29detection errors in total.

While the invention has been described in conjunction with the specificembodiments thereof that are proposed as examples, it is evident thatmany alternatives, modifications, and variations will be apparent tothose skilled in the art. Accordingly, embodiments of the invention asset forth herein are intended to be illustrative, not limiting. Thereare changes that may be made without departing from the scope of theinvention.

What is claimed is:
 1. A method for detecting marks, comprising:receiving a data signal from a channel; convolving a predeterminedpattern with a partial response target that characterizes the channel tocalculate a template; and matching the data signal to the template thatcorresponds to the predetermined pattern transmitted over the channel todetect marks, prior to decoding the data signal into a decoded bitstream.
 2. The method of claim 1, wherein matching the data signal tothe template further comprises: matching the data signal to a sync marktemplate that corresponds to a sync mark pattern transmitted over thechannel to detect sync marks in the data signal, the sync marks beingused to frame user data in the data signal.
 3. The method of claim 1,wherein matching the data signal to the template further comprises:matching the data signal to a non-uniformly weighted template.
 4. Themethod of claim 1, further comprising: weighting the templatenon-uniformly to generate a second template.
 5. The method of claim 1,wherein matching the data signal to the template further comprises:calculating correlation coefficients between the data signal and thetemplate; and detecting the marks based on the correlation coefficients.6. The method of claim 5, wherein detecting the marks based on thecorrelation coefficients further comprises: detecting peak tops in thecorrelation coefficients that are larger than neighboring correlationcoefficients; and comparing the peak tops to a threshold to detect themarks.
 7. The method of claim 5, wherein calculating the correlationcoefficients between the data signal and the template further comprises:storing a pre-calculated Euclidean norm of the template; and calculatingthe correlation coefficients using the stored Euclidean norm of thetemplate.
 8. The method of claim 1, wherein matching the data signal tothe template further comprises: matching the data signal to the templateto detect the marks, prior to using Viterbi decisions to decode the datasignal.
 9. A signal processing circuit, comprising: a pre-decodingportion configured to receive a signal corresponding to a bit streamthat includes marks having a predetermined pattern, process the signal,and output a data signal for decoding; a decoder configured to decodethe data signal into a decoded bit stream; a template module configuredto convolve a sync mark pattern with a partial response target thatcharacterizes a channel over which the data signal is transmitted tocalculate a sync mark template; and a mark detection module configuredto match the data signal to the sync mark template that corresponds tothe predetermined pattern to detect the marks.
 10. The signal processingcircuit of claim 9, wherein the template module is configured tonon-uniformly weight the sync mark template to generate a second syncmark template.
 11. The signal processing circuit of claim 9, wherein themark detection module further comprises: a correlation module configuredto calculate correlation coefficients between the data signal and thetemplate; and a detector configured to detect the marks based on thecorrelation coefficients.
 12. The signal processing circuit of claim 11,wherein the detector is configured to detect peak tops of thecorrelation coefficients that are larger than neighboring correlationcoefficients, and compare the peak tops to a threshold to detect themarks.
 13. An electronic system, comprising: a pick-up unit configuredto generate a signal corresponding to a bit stream, the bit streamincluding marks having a predetermined pattern; a pre-decoding portionconfigured to process the signal, and output a data signal for decoding;a decoder configured to decode the data signal into a decoded bitstream; a template module configured to convolve a sync mark patternwith a partial response target that characterizes a transmission channelover which the data signal is transmitted to calculate a sync marktemplate; and a mark detection module configured to match the datasignal to the sync mark template that corresponds to the predeterminedpattern to detect the marks.
 14. The electronic system of claim 13,wherein the pick-up unit is configured to generate the signal inresponse to at least one of an electromagnetic signal transmitted overair, magnetic field changes on a magnetic storage medium, and opticalproperty changes on an optical storage medium.
 15. The electronic systemof claim 13, wherein the template module is configured to non-uniformlyweight the sync mark template to generate a second sync mark template.16. The electronic system of claim 13, wherein the mark detection modulefurther comprises: a correlation module configured to calculatecorrelation coefficients between the data signal and the template; and adetector configured to detect the marks based on the correlationcoefficients.
 17. The electronic system of claim 16, wherein thedetector is configured to detect peak tops of the correlationcoefficients that are larger than neighboring correlation coefficients,and compare the peak tops to a threshold to detect the marks.